Multiple retort stoker



. April 9, 1946- G. P. JACKSON 2,398,009

MULTIPLE RETORT STOKER Filed Dec. 18, 1943 3 Sheets-Sheet l INVENTOR.GeorGe P. J ackson April 9, 1946 G. P. JACKSON I MULTIPLE RETORT STOKERFiled Dec. 18, 1943 3 Sheets-Sheet 2 INVENTOR. G-QoY -JP l ac WSoM April1946- G. P. JACKSON 2,398,009

MULTIPLE RETORT STOKER Filed Dec. 18, 1945 3 Sheets-Sheet 3 INVENTOR. C7caree J acksoh fl RNE Y Patented Apr. 9, 1946 MULTIPLE RETORT STOKERGeorge P. Jackson, Flushing, N. Y., assignor to Combustion EngineeringCompany, Inc; New

York, N. '1.

Application December 18, 1943., Serial No. 514,800

6 Claims.

This invention relates to stokers and particularly to improvements inmultiple retort underfeed stokers.

Conventional multiple retort strikers comprise a number of retorts andtu'yeres extending longitudinally of the furnace and arranged inalternation across the width of the furnace. Each retort is provided atits front'end with a ram which reciprocates through a ram box extendingfrom below a fuel hopper into the retort and delivers the fuel droppinginto' the ram box from the hopper by pushing it into the retort. Thefuel is then moved along each retort toward the rear of the furnace bymeans of pushers which are arranged for reciprocation in the bottom ofthe retort. air for combustion into the burning mass of fuel being movedalong the retort. At the rear ends of the retorts there are overfeedsections that receive the burning fuel from the retorts and The tuyeresadjacent each retort deliver tuyeres for completing the burning of thefuel before it is delivered to the ash receiving means. Heretofore thepractice in multiple retort stoker construction has been to have anindividual ram for each retort. One of the limitations in burn-' ing thefuel has been due to the Width of the retorts which was established bythe width of the ram that feeds it. The Width of the ram was made ampleto prevent the packing of the fuel in the ram boxand because ram boxesare costly to make it was considered desirable to use as few of them aspossible which led to increasing their width and that of the retorts toan undesirable degree. I

In operation it has been found that the fuel bed forms in ridgeslongitudinally of the furnace because most of the burning of the fueloccurs above the tuyere surfaces and to a limited extent above theretorts. through the tuyres does not completely penetrate the wide fuelbed over the retorts. To partly compensate for this unequal distributionof the air through the fuel bed the stoker must be operated with athicker fuel bed than would be the case where air admission were moreuniform. Furthermore, as the fuel .is carried along through the furnaceby the action of the pushers, the action of the pushers has been foundto be effective in distributing and moving the fuel above the retortsbut not so eifective in moving the fuel along the top of the adjacenttuyere rows. Due'to the present widths of the tuyeres the longitudinalmovement along the middle of the tuyeres is found to be sluggish and ifthe fuel ash becomes soft at a comparatively low temperature and hasclinkering tendencies,the fuel does not move down the middle of thestoker tuyeres but adheres thereto partially shutting on the air andfurther aggravating the difficulties in operating the stoker.

This is because the air admitted An object of this invention is toprovide an improved multiple retort :stoker to overcome the abovediiiiculties.

In the accompanying drawings:

Figure 1 is a sectional elevation taken longitudinally through a stokerembodying the invention;v

Figure 2 is a sectional plan view on line 22 of Figure 1; I

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a section on line 4-4 of Figure 2; and

Figure 5 is a view similar to .Figure 2 showing another embodiment ofthe invention.

The operating parts of the stoker shown in Fig. 1 are in general thesame as those disclosed in the patent to Zinkernagel et al., 2,164,100,issued June 27, 1939. The 'stoker drive includes a drive shaft l0operating through reduction gearing, designated as a whole by thenumeral H in Figure 1, to drive a crank shaft 12 having cranks 13 forreciprocating the rams M in ram boxes 15 through connecting rods '16..Other connecting rods 11 act through bell-cranks l8 and the adjustiabl'estepped cams 20 to actuate the push rod assembly 21 to reciprocate thefuel pushers 22 in the retorts 25.

As appears in Fig. 2, the retorts 25 and tuyeres 26 extendlongitudinally of the stoker and are arranged in alternation. Retorts 25are grouped preferably two to a ram box I5; thus one ram 14 as itreoiprocates delivers fuel from the hopper through one ram box l5 to theforward ends of two adjacent retorts Hi. The pushers 22 at the bottom ofthe retorts advance the fuel tothe rear of the stoker. Alternating withthe retorts 25 are the tuyeres so that there is a tuyere 26 between thetwo retorts 25 fed by one ram. M and also a tuyere 26A between each suchpair of retorts and the adjacent pair of retorts, the tuyeres 25A thusbeing opposite the spacers 28 intervening between two rams I4 andassociated boxes. The forward ends 21 of the tuyeres 25 facing the ramsM are spaced rearwardly from the rams and shaped wedgelike to divide thefuel flowing from the ram box I 5 into two separate streams, one foreach of two adjacent retorts 25. Ram boxes iii are spaced aparttransversely of the stoker and one tuyere 26A is in longitudinalalignment with the space intermediate the ram boxes. Since thisintervening space 28 may be wider than the aligned tuyere 26A the lattermay be flared at its front end so as to meet flushly with the sides ofthe adjacent ram boxes l5 and form a smooth side wall for the flow ofthe fuel therealone.

Figs. 3 and :4 show the tuyeres 2% superimposed on wind boxes 28 whichsupport them. Fig. I3 shows :a cross-section through the front taperedend 21 of a 'tuyere "26 which divides the flow of fuel from the ram boxl5 to the two adjacent retorts.

In Figure 5 showing a modification of the in vention several rams 34 arearranged side by side transversely of'the stoker in a'single ram box 35,there being no partitions between rams,

34. Consequently the fuel is delivered substantially uniformly acrossthe width of the stoken, I

The rams 34 deliver the coal from the hopper to the retorts 25 but donot all'move forwardly at the same time. The ram movements preferably Inoperation, the improved stoker overcomes the difficulties outlined atthe beginning of this specification because both the tuyeres and retortshave been reduced in width compared to conventional arrangements whilethe advantages of the wide rams andframboxes as to cost and non-packingof fuel have been retained. Preferably the tuyeres and retorts are madeof about the same widthand due to their being much nar- V rower thanheretofore, the distribution across the stoker of air through the fuelbed is-more uniform. The narrower width of the fuel bed above the retortbottom permits a better penetration of theair therethrough. The narrowerwidth of the fuel bed above a tuyere assures a more uniform movementalong the stoker of the fuel covering the entire width of the tuyereeven when a clinkering coal is used because it is drawn along bythe'sides of the body of moving coal in the retorts. Consequently theair stoppage over a tuyere by the fuel clinkering to the middle of itstop surface is avoided. The improved stoker therefore provides a moreuniform burning of the fuel throughout the entire fuel bed.

What I claim is: a

1. In an underfeed stoker having a plurality of spaced pairs of retortswith tuyeres intervenretorts for moving the fuel toward the rearthereof; and means for delivering air through the tuyeres into the fuelabove the adjacent retorts and tuyeres.

' 3; In an underfeed tuyres arranged in alternation transverselythereof; a fuel hopper; a ram box extending the. full width of thestoker communicating with the ends of all the retorts; a plurality ofadjacent contacting reciprocating rams in said ram box each deliveringfuel from the hopper through said ram box to at least two retorts; meansat the tuyre ends facing the rams spaced therefrom and shaped to dividethe fuel therefrom into the adjacent retorts; means for reciprocatingthe rams; means in the retorts for moving the fuel toward the rearthereof; and means for deliver-'- ing air through the tuyres into thefuel above th adjacentretorts and tuyres.

4. In an underfeedstoker. havinga multiplicity of retorts and tuyeres ofrelatively narrow width and of substantial length arranged inalternation transversely of the stoker; a fuel hopper and a conduitextending therefrom to the front ends of at least two adjacent retorts;feeding means for delivering fuel from the hopper through the conduit tosaid retort ends; means in each of the retorts foradvancing fuellongitudinally along the retorts and the adjacent tuyeres; meanspositioned between said two retorts and facing said feeding means inspaced relation to the latter and shaped to divide the fuel flow fromsaid feeding means. into the adjacent retorts; means for operating saidfeeding means, means for operating said fuel advancing means; and meansfor delivering air through the tuyres into the fuel above the adjacentretorts and tuyres.

5. In an underfeed stoker having a multiplicity of retorts and tuyres ofrelatively narrow width 40 and of substantial length arranged inalternaversely of the stoker of relatively narrow Width and ofsubstantial length; a fuel hopper and ram boxes spaced transversely ofthe stoker extending from said fuel hopper to the front ends of bothretorts of each pair; a reciprocating ram in each box for deliveringfuel from the hopper through the ram box to said'retorts'; means at theend of each tuyere facing said rams shaped to divide the fuel flowdelivered thereby into the adjacent retorts; means for reciprocating therams; reciprocating pushers in the retorts for moving the fuel towardthe rear thereof; means for reciprocating said pushers; other tuyresdisposed in the spaces between adjacent'pairs of retorts and alignedwith the spaces between ram boxes; and means for delivering air throughall of the tuyres into the fuel above the adjacent retorts and tuyeres.

2. In an underfeed stoker having retorts and tuyeres arranged inalternation transversely thereof; a fuel hopper; a ram box extending thefull width of thestoker communicating withit'he front ends of all theretorts; a plurality of reciprocating rams for delivering fuel from vthehopper j acent retorts and tuyres.

tion transversely of the stoker; a fuel hopper and a ram box extendingtherefrom to the front ends ofat least two adjacent retorts; areciprocating ram 'for delivering fuel from the hopper through the rambox to saidretort ends; reciprocating pushers in each of the retorts foradvancing fuel longitudinally along the retorts and the adjacenttuyeres; means positioned between said two'retorts and facing said ramin spaced relation to the latter and shaped to divide the fuel flow fromsaid ram into the adjacent retorts; means for reciproc'ating'said ram;means for reciprocating said pushers; and means for delivering airthrough the tuyeres into the fuel above the adjacent retorts and tuyres.

6. In an underfeed stoker having a multiplicity of retorts and tuyeresof relatively narrow width and of substantial length arranged inalternate parallel rows transversely of the stoker; a fuel hopper and aram box extending therefrom to the front ends of each of two adjacentretorts; a reciprocating ram for delivering fuel from the hopper througheach ram box to said retort ends; reciprocating pushers in each of theretorts for advancing fuel longitudinally along the retorts and. theadjacent tuyeres toward the rear thereof; means positioned between eachsaid two retorts and-facing said rams in spaced relation to the latterand'shaped to divide the fuel flow from said rams into each of theadjacent two retorts; means for reciproca'tingsaid rams; means forreciprocating said pushers; and means for delivering air through thetuyres into the fuel above the ad- GEORGE P. JACKSON.

stoker having retorts and

